/Engine/Source/Runtime/Core/Public/Misc/OutputDeviceFile.h
Provides a thread-safe serialization interface with a background thread doing the actual writes. [] tags identify which thread owns a variable or function
class FAsyncWriter : public [FRunnable](API\Runtime\Core\HAL\FRunnable), public [FSingleThreadRunnable](API\Runtime\Core\Misc\FSingleThreadRunnable), public [FArchive](API\Runtime\Core\Serialization\FArchive)